My belief remains that no complete "alternative" Tremonisha has been recorded because of the cost and likelihood of financial loss. An "angel" investor would be required.
The Joplin score lacks full orchestration. Would the small versions prepared for current performances be accepted by the public in complete recorded form? I would like to see another version but I may belong to a small minority.
What were the dates on the court cases? That has a bearing on the current status as well. Court action may no longer be possible except with regard to the 1975 Schuller-orchestrated version (and old cases that are undecided- which I doubt).
The Zimmerman recordings remain available in a box set at reasonable price.